Henry could hardly believe his eyes as the much-coveted opportunity, of which he had been so many days disappointed, at last presented itself, and he waited with more than his usual caution until the plan of attack should be developed by his great antagonist. Parma, on his side, pressed the hand of Mayenne as he watched the movement, saying quietly, "We have already fought our battle and gained the victory." He then issued orders for the whole battalia--which, since the junction, had been under command of Mayenne, Farnese reserving for himself the superintendence of the entire army--to countermarch rapidly towards the Marne and take up a position opposite Lagny. La Motte, with the rearguard, was directed immediately to follow. The battalia had thus become the van, the rearguard the battalia, while the whole cavalry corps by this movement had been transformed from the vanguard into the rear. Renty was instructed to protect his manoeuvres, to restrain the skirmishing as much as possible, and to keep the commander-in-chief constantly informed of every occurrence. In the night he was to entrench and fortify himself rapidly and thoroughly, without changing his position. Under cover of this feigned attack, Farnese arrived at the river side on the 15th September, seized an open village directly opposite Lagny, which was connected with it by a stone bridge, and planted a battery of nine pieces of heavy artillery directly opposite the town. Lagny was fortified in the old-fashioned manner, with not very thick walls, and without a terreplain. Its position, however, and its command of the bridge, seemed to render an assault impossible, and De la Fin, who lay there with a garrison of twelve hundred French, had no fear for the security of the place. But Farnese, with the precision and celerity which characterized his movements on special occasions, had thrown pontoon bridges across the river three miles above, and sent a considerable force of Spanish and Walloon infantry to the other side. These troops were ordered to hold themselves ready for an assault, so soon as the batteries opposite should effect a practicable breach. The next day Henry, reconnoitering the scene, saw, with intense indignation, that he had been completely out-generalled. Lagny, the key to the Marne, by holding which he had closed the door on nearly all the food supplies for Paris, was about to be wrested from him. What should he do? Should he throw himself across the river and rescue the place before it fell? This was not to be thought of even by the audacious Bearnese. In the attempt to cross the river, under the enemy's fire, he was likely to lose a large portion of his army. Should he fling himself upon Renty's division which had so ostentatiously offered battle the day before? This at least might be attempted, although not so advantageously as would have been the case on the previous afternoon. To undertake this was the result of a rapid council of generals.